Direct-reading radiogoniometer



\ DIRECT READING RADIOGONIOMETER J. MMMM QUE u 2,033.73

2 Sheets-Sheet 2 Patented Mar. 10, 1936 UNIT-ED STATES PATENT OFFICE Application October 19, 19357,*Serial No. 4558700 In Belgium January 4, 1935 9 Claims.

-The present inventionrelates to adirect reading radiogoniometer of the type in which the electrodes of a rare gas tuberare subjected to the differences of potential created at the `.outlet terminals of a receiving apparatus 'for electric waves supplied-With high frequency current by an exploring system with which the `said tube rotates at a speed such that in consequence of the persistence of the impressions on the retina, the fcurve described by thetube during its illumination appears in a permanent manner on a screen.

Radiogom'ometers of this typeare known'in which a rare gas tuberarranged perpendicularly r to the axis about which it rotates, is subjected to the variable difference ofpotential created at the outlet of a receiver, the regulations Vbeing such that the potential of illumination 'of the tube is greater than `the potential obtained at the outlet of the receiver for the'minima of Vthe electromotive force induced in the exploring rsystem. lSuch a tube therefore remains illuminated as long as the intensity of reception in the exploring system is suiicient for the outlet po'- tential of the receiver to be higher than the illuminating potential andA is extinguished as soon asthis intensity becomes insufficient; it operates on `the all or none principle. The curve or trajectory described by this tube therefore appears through a screen perpendicular to the axis of rotation, as two luminous circumferential bands separated by two dark zones corresponding .to the extinction of the tube in the vicinity of the two reception minima in the rotating exploring system.

Other apparatuses are known in which, in consequence of certain ccnstructional peculiarities of the receiver, the tube is normally extinguished, and only lights up when `the intensity of reception falls below a certain value. In these apparatuses, there are only seen on thescreen two small luminous marks corresponding to the positions of the minimum of reception in the rotating exploring v system. The .remainder of the curve of the tube .does not appear, since Vthe Vlatter is extinguished during almost the whole of the rotation. In these apparatuses, therare :gas tube also operates Aon the all or none principle.

The radiogoniometers of this kind have the defect that their operation is based onthe sudden passage of the outlet potential on each side of the illumination potential inthe vicinity of the vminima. This Vnecessitates for each emission torbe observed, very precise regulations of the 55- 4amplification I (Cl. Z50-11') On `the other hand, itis sometimespossible for certain regulations Aof the outlet potential, to obtain very small extinction'arcs (or those of illumination according to the type of radiogoniometer), *even ifthe minima are soft and ofV bad quality. Itis not, therefore, known whatv degree of credence `can =be attributed tothe reading thus obtained.

" In other cases, on'the'contrary,`it may be impossible tond regulations which give illuminations or extinctionsoi:` the tube'which are stable, inparticular whenthe minima'are soft, in consequence 'of the slight intensity of reception.

Sometimes, again, Vthe rare gas tubes are only extinguished at a potential lower than their normal extinctionpotental, and are only illuminated at a potential higher 'than their normal illuminationI potential. These tubes are thus subjected'to a `phenomenon similar to hysteresis, which has for effectto shift the zones of extinction or the kzones of illumination-on the screen and to consequently give inaccurate readings.

"The present invention obviates these drawbacks,

-To this end, there is used in the radiogoniometer according to the invention, vaY rare gas tube in which the arrangement of the electrodes is such that'the length of the luminous column is a function of the applied `potential above the threshold illumination potential. VSuch tubes are known and are currently employed as luminous indicators `of tuning in radio' receivers. They comprisegfor example, a lengthened cathode and a very short anode placed closeto one extremity of the cathode; certain tubes comprise, furthermore, an auxiliary electrode-to regulate'the functioningiof :the tube.

In the-radiogoniometer according to the invention, there is applied'between the cathode and the anode of the rare gas tube aV Variable vdifference of potential such that the tube remains constant-lylluminated andthe variation of which is a function of `'the amplitude of the :electrometive force'induced in the exploring system.

With aY radiogoniometer according to the invention, the diiculties of regulating thereceiver andthe tube to obtain ,small areas of extinction or of illumination do not exist, ,since the tube is constantly illuminated. The aspect of the curve which represents the variation lof the electrometive force inducedin the rotating exploring system, permits of taking into account the conditions under which the measurements are made. Even if the minimaare'not very accentuated, Ait is possibleto'atleast make 'approximatereadings A radiogoniometer according to the invention thus presents the'same advantages as those in which the outlet current of the receiver is sent into a mirror galvanometer which rotates in synchronism with the exploring system and of which the luminous beam, reflected by the mirror, describes on a screen a curve representing the variation of the amplitude of the electromotive force induced in the exploring system during the rotation thereof. It presents, as compared with these apparatuses, the very appreciable advantage of `costing much less, of being strong, and of permitting, in consequence of the slight inertia of the phenomena of luminescence, the exploring system to be rotated much more rapidly, which may sometimes be desirable.

If the rare gas tube is directed, with respect to its axis of rotation, in such manner as to meet the latter at a fixed distance, there is obtained by transparency through a screen perpendicular to the axis of rotation, a luminous surface limited, on the one hand, by a circumference of radius equal to the distance from the base olf the luminescent column to the axis of rotation, and, on the other hand, by a curve of polar shape representing the variation of the amplitude of the electromotive force induced in the rotating exploring system during the rotation thereof.

The curve of polar shape limiting the said luminous surface is located externally or internally of the circumference described by the base of the luminescent column according to whether the head of the luminescent column is further away from or nearer to the axis of rotation, than the base.

Other peculiarities and details of the invention will appear in the course of the description of the drawings annex-ed to the present specification and which represent diagrammatically and simply by way of example, a few modifications of embodying a radiogoniometer according to the invention.

Figure 1 shows a first embodiment of a radiogonimeter according to the invention;

Figure 2 shows a modification of a part of this radiogoniometer;

Figures 3 to 6 show different modifications of luminous surfaces seen through the screen of a radiogoniometer according to the invention;

Figures 7 to 10 are diagrams representing diagrammatically the amplitude of the electromotive force applied between the cathode and the anode of the rare gas tube as a function of the angular position of the rotating exploring,

system.

Figure 11 shows another embodiment of a radiogoniometer according to the invention.

In these different figures, the same reference signs indicate identical elements.

In Figure 1, there is shown a rotating direction-finder exploring system 2 constituted 'by a frame with vertical axis. 'I'he high frequency current created in this system by a high frequency oscillation is collected by rubbing contacts 3 and 4. It is amplified in a receiving apparatus of electric waves 5 comprising for example, in known manner, high frequency am.

plification stages, a detection stage, and low frequency amplification stages. furthermore, comprise a low frequency detection stage or rectification stage, itself followed by an amplifier, for example of the, type called continuous current amplifier.

The intensity of the current at the outlet of the receiver 5 is supposed to vary in the same This receiver may,v

sense as the amplitude of the electromotive force induced in the exploring system. The outlet terminals 5a and 5b are connected respectively to the extremities 'Ia and 'Ib of a resistance l. In the case of Figure 1, these connections are presumed as made in such manner that the current circulates in the resistance 'lfrorn the extremity 'Ib to the extremity la. In consequence of the potential drop in this resistance, the extremity 'la is consequently at a potential lower than that of the opposite extremity lb. A total difference of potential due to the combination of a source of constant potential I2 and the potential drop in the resistance 'I is applied between the cathode 8a and the anode 8b of a rare gas tube 8 (for example a Neon lamp) rotating in synchronism with the frame 2 and arranged perpendicularly to its axis of rotation below a transparent screen 9. This application is realized by the intermediation of rubbing contacts IE) and I I, rotating with the rare gas tube 8. The latter preferably comprises, with a view to facilitate the illumination, an auxiliary electrode 8d connected by a rubbing contact I3 and a high resistance I4, to the cathode 8a.

If we represent by abscissae the angles of rotation of the rotating exploring system, the differences of potential applied between the cathode and the anode are represented by a curve of the nature of the curve 2I of Figure '7. The ordinates of this curve are, in fact, equal at each instant to the algebraical sum of the difference of the constant potential supplied by the source I2 (and represented by the straight line 22 parallel to the axis of the absciss) and of the drop of potential produced in the resistance 'l by the outlet current of the receiver which varies in the same sense as the amplitude of the electromotive force induced in the frame.

The difference of potential developed by the source of current I2 being such that the tube 8 is constantly illuminated and this tube being arranged in such manner that the head of the luminous column is further away from the axis of rotation than the base of the column, during the rotation of the tube, the luminous surface which appears through the screen 9 is similar to that represented on Figure 3. This surface is limited internally by a circumference I5 of radius equal to the distance from the base of the luminescent I column to the axis of rotation, and externally by a curve I 6 of polar form having two retracted portions ISa corresponding to the two minima of reception in the frame 2, that is to say, to the positions of this frame perpendicular to the direction in which is located the emitting station to be found. y

Instead of arranging the rare gas tube as shown in Figure 1, it could alsol be arranged as sho-wn in Figure 2, so that the head of the luminescent column is closer to the axis of rotation of the tube than the base of the column.

The luminous surface which appears through the screen 9 is of the nature of that shown in Figure 4. It is limited externally by a circumference I5 similar to the circumference I5 of Figure 3 and internally by a curve I'I having two portions I'Ia receding from the axis of rotation and which correspond to the minima of reception in the exploring system.

The resistance. 'I could also be connected to the outlet terminals of the receiver in such manner that the current passes through it from the extremity 'la to the extremity 1b. This connection could be established by shifting a reverser 2Il Cil from the position shown in full lines to the position shown in broken lines.

In this fresh connection, the drop of potential in the resistanceV 'Ion the passage of the'current is such that the extremity 'Ia to which is connected the source of current I2 is subjected to a potential greater than that of the opposite extremity lb. The algebraical sum of the potential supplied by the source I2 and by the drop of potential in the resistance I is therefore such that the total diiference of potential applied between the cathode and the anode diminishes when the outlet current of the receiver increases. This difference of potential is shown by the curve 23 of Figure 8.

If the diierence of potential developed by the source of current I2 is such that the tube is illuminated to a comparatively considerable distance from the base,l any increase of current at the outlet of the receiver 5 has for effect to diminish the length of the luminescent column.

If the rare gas tube is arranged as in the Figure 1, the luminous surface which appears through the screen 9 is of the nature of that shown in Figure 5. It is limited externally by a curve I8 having two projecting portions I8a corresponding to the two minima of reception in the exploring system.

If the tube is arranged as shown in Figure 2, the luminous curve which appears through the screen 9 is of the-nature of that shown in Figure 6. It is limited internally by a curve I9 having two retracted portions Ilia approaching the axis of rotation, and which correspond to the minima of reception in the exploring system.

Curves similar to the curvesV of Figures 4 to 6 could also be obtained by using a receiver constructed in such manner that the intensity of the output current varies inversely to the amplitude of the electromotive force induced in the exploring system.

In this case, in fact, if We suppose in the rst place that the current ilows through the resistance i so that the drop of potentialis added to the constant difference of potential supplied by the source I2, the curve representing the amplitude of the potential applied between the cathode and the anode as a function of the angular position of the rotating exploring system is Vof the character of the curve 24 of Figure 9.

rIlhis curve is similar to the curve 23 of Figure 8' and shows that the total difference of potential applied between the cathode and the anode of the rare gas tube varies inversely to the amplitude of the electromotive force induced in the rotating exploring system.

If we now suppose that this vsame receiver is connected to the resistance 'I in such manner that the drop of potential is deducted Vfromthat supplied by the source I2, the curve representing the amplitude of the potential applied between the cathode and the anode is of the character of the curve 25 of the Figure 10.

This curve is similar to the curve 2l of Figure 7, and shows that the difference of potential applied between the cathode and the anode varies in the same sense as the amplitude of the electrornotive force induced in the rotating exploring ltion of the elements taking part in the embodiment without departing from the scope of the present patent.

Thus, it is obvious that the rare gas tube used could be constituted otherwise than as represented, that it need not necessarily be filled with neon nor be arranged perpendicularly to the axis of rotation.

In particular it could, as shown in Figure 11, be arranged parallel to the axis of rotation. The luminous column would then be observed on a cylindrical screen 9. The movable head of the column would then describe a curve 2l similar to a sinusoid.

In turning over the tube end for end or by reversing the outlet terminals of the receiver to which the extremities of the resistance I are connected, it would be possible to modify the position of this sinusoid on the screen.

Whatever might be the embodiment adopted for the apparatus, it would be possible in known manner to combine an open aerial to the rotating exploring system in order to determine the direction in which lies'the emitter.

Some other rotating exploring system than a frame can also be employed. In this case, there are obtained other curves than those of Figures 3 to 6.

What I claim is:

1. A direct reading radiogoniometer, comprising a rotating direction-finder exploring system., a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tube of the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the Ythreshold illumination potential, means for rotating this tube synchronously with said exploring system, means for applying between the cathode and the anode of said tube the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a diierence of potential such that the tube L remains constantly illuminated despite the application of said variable difference of potential, a screen on which the illumination of said tube appears, and means for rotating said exploring system and tube at such a speed that by reason of i the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

2. A direct reading radiogoniometer, comprising a rotating direction-finder exploring sysploring system, a rare gas tube of the type in which the electrodes are so arranged that the length ofthe luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system around an axis perpendicular to it, means for applying between the cathode and the anode of said tube the variable difference of potential created at the outlet terminals of said receiving apparatus, means H for applying between the cathode and the anode of said tube a difference of potential such that the tube remains constantly illuminated despite the application of said variable dierence of potentiaLa screen on which the illumination of said tube appears, and means for rotatingv said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its yillumination appears in a permanent manner on said screen.

3. A direct reading radiogoniometer, comprising a rotating direction-lnder exploring system a Vreceiving apparatus of electricwaves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tube of the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system, means for appplying between the cathodeA and the anode of said tube the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a difference of potentialsuch that the tube remains constantly illuminated despite the application of said variable dierence of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

4. A direct reading radiogoniometer, comprising a rotating direction-lnder exploring system, a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tube of the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said eX- ploring system, around an axis perpendicular to it and with its base cle-ser to this axis than the head of the luminescent column, means for applying between the cathode and the anode of said tube the variable diierence of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a dlierence of potential such that the tube remains constantly illuminated despite the application of said variable -z difference of potential, a screen perpendicular to the of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

5. A direct reading radiogoniometer, comprising a rotating direction-iinder exploring system, a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tube of the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system around an axis perpendicular to it and with its base cler to this axis than the headof the luminescent column, means for applying between the cathode and the anode of said tube and in Ythe same sense as the amplitude of the electromotive force induced in the exploring system the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a difference of potential such that .the tube remains constantlyilluminated despite the application of said variable difference of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

6. A direct reading radiogoniometer, comprising a rotating vdirection-finder exploring system, a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tubeof the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system around an axis perpendicular to it and with its base closer to this axis than the head of the luminescent column, means for applying between the cathode and the anode of said tube and inversely to the amplitude of the electromotive force induced in the exploring system the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a difference of potential such that the tube remains constantly illuminated despite the application of said variable diierence of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

7, A direct reading radiogoniometer, comprising a rotating direction-finder exploring system, a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring system, a rare gas tube of the type in which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential; means for rotating this tube synchronously with-said exploring system around an axis perpendicular to it and with its base further removed from this axis than the head of the luminescent column, means for applying between the cathode and the anode of said tube the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a difference of potential such that the tube remains constantly illuminated despite the application of said variable difference of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

8. A direct reading radiogoniometer, comprising a rotating direction-finder exploring system, a receiving apparatus of, electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploring sys-` tem, a rare gas tube of the type in which the electrodes areso arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system'around an axis perpendicular to it and with its base further removed from this axis than the head of the luminescent column, means for applying between the cathode and the anode of said tube and in the same sense as the amplitude of the electromotive force induced in the exploring system the variable diierence of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a difference of potential such that the tube remains constantly illuminated despite the application of said variable difference of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its i1- lumination appears in a permanent manner on said screen. I

9. A direct reading radiogoniometer, comprising-a rotating direction-finder exploring system, a receiving apparatus of electric waves, means for applying to said receiving apparatus the high frequency current generated in said exploringV system, aY rare gas tube of the typein which the electrodes are so arranged that the length of the luminous column is a function of the potential applied between the cathode and the anode above the threshold illumination potential, means for rotating this tube synchronously with said exploring system around an axis perpendicular to it and with its base further removed from this axis than the head of the luminescent column, means for applying between the cathode and the anode of said tube and inversely to the amplitude of the electromotive force induced in the exploring system the variable difference of potential created at the outlet terminals of said receiving apparatus, means for applying between the cathode and the anode of said tube a dierence of potential such that the tube remains constantly illuminated despite the application of said variable difference of potential, a screen, perpendicular to the axis of rotation of the said tube, on which the illumination of the latter appears, and means for rotating said exploring system and tube at such a speed that by reason of the persistence of the impressions on the retina the course described by the tube during its illumination appears in a permanent manner on said screen.

JEAN MARIQUE. 

